Teams in the National Football League playoffs obviously have been doing all they can to win and advance, but in too many cases the players seem to be doing too much.

There’s a difference in playing hard and playing viciously, a distinction apparently lost on some of the players.

How many times in the playoff games have we seen head-butting, leg-whipping, cork-screwing, out-of-bounds late hits and other tactics, both vindictive and dumb?

No one has ever claimed that football is for sissies. As a coach remarked years ago when it was mentioned that the game is a contact sport: &uot;No, it’s not a contact sport; it’s a collision sport.&uot;

That’s okay, so long as the collisions are within the rules.

In the playoff games, players been helped off the field, and sometimes to locker rooms and medical checks, because of illegal practices.

These practices rarely escape the attention of the officials, which means that the perpetrators are hurting their teams with penalties.

In Sunday’s games only, the four teams committed a total of 29 penalties which cost them 271 yards.

One mystery is how a player can advance from school-boy football to high school, to college and then to the pros without learning more about the rules. Then, perhaps, some of them aren’t all that blessed with gray matter to start with.

Answer this, if you can: Why is it that a pass catcher can know exactly where the sideline stripe is, keep his feet inbounds while catching the ball, while a defender sometimes doesn’t seem to have any idea where the chalk is when making a tackle? And he doesn’t even have to worry about catching a pass.

So much for this week’s homily.

Now, four teams are left in the running for the 37th Super Bowl to be played Jan. 26 at San Diego.

Two will be left after Sunday’s battles between Tampa Bay and Philadelphia, and Tennessee and Oakland.

Only one of last weekend’s games was that exciting &045; Tennessee’s 34-31 overtime victory over Pittsburgh. Philadelphia took care of Atlanta and Michael Vick, Tampa Bay eliminated San Francisco, and Oakland ended the New York Jets’ season.

I’m going with the two home teams. Tampa Bay has to travel from its warm climate to the wintry weather of Philadelphia, and Tennessee must cross the country to meet an Oakland team that seems to be on a mission.

Whichever teams win, it is to be hoped that all four play hard but clean.

(Hoyt Harwell is a retired Associated Press Correspondent who covered major sports in Alabama for 26 years. Harwell lives in Hoover. (e-mail: hharwell@bellsouth.net